Isomeric decays in 126 Cd, 128 Cd, 130 Cd. s

Isomeric decays in Isomeric decays in 126126Cd, Cd, 128128Cd, Cd, 130130Cd.Cd.s

-The 8+ seniority isomer in 130Cd and its decay has been measured for the first time and no evidence for N=82 shell quenching at Z=48 was observed.-Three isomeric states have been identified in 128Cd. The level scheme was constructed unambiguously based on the γγ coincidenceand lifetime analysis performed for the first time in this nucleus. Theisomeric decay pattern is selective to the structure of the populatedstates and their leading π or ν configuration.-Five new γ transitions have been observed in the isomeric decay of 126Cd. Half-life and coincidence analysis was performed for the first time in this nucleus. The γγ coincidence analysis reveal the existence of two competing branches depopulating the level at 4507 keV although the ordering of the transitions between that level and the one at energy of 2439 keV could not be established due to the non observation of linking transitions between the two branches and/or prompt character of the transitions below the isomer.

Summary & Conclusions :Summary & Conclusions :

128Cd LSSM

LSSM calculationsLSSM calculations130130CdCd SM-1: π ( p1/2, s, d, g ) ν ( g7/2, s d, h11/2 )

SM-2: π ( p1/2, g9/2 ) ν ( g7/2, s d, h11/2 )

88Srcore

126,128126,128CdCd ππ ( p, ( p, f5/2, , g9/2 )) νν ( ( g7/2, d, , d, ss1/21/2, , h11/2 ))

7878Ni coreNi core

L. Cáceres1,2, M. Górska1, A. Jungclaus2,3, M. Pfützner4, H. Grawe1, F. Nowacki5, K. Sieja1, S. Pietri3, D. Rudolph7, Zs. Podolyák6, P. H. Regan6, E. Werner-Maleto4, P. Detistov8, S. Lalkovski8,9, V. Modamio2, J. Walker2, K. Andgreg10, P. Bednarczyk1,11, J. Benlliure12, G. Benzoni13, A.M. Bruce9, E. Casarejos12, B. Cederwall10, F. C. L. Crespi13, P. Doornenbal1,15, H. Geissel1, J. Gerl1, J. Grębosz1,14, B. Hadinia10, M. Hellström7, R. Hoischen1,7, G. Ilie15, A. Khaplanov10, M. Kmiecik11, I. Kojouharov1, R. Kumar16, N. Kurz1, K. Langanke1, A. Maj11, S. Mandal17, F. Montes1, G. Martínez-Pinedo1, S. Myalski11, W. Prolopowicz1, H. Schaffner1, G. Simpson18, S. J. Steer6, S. Tashenov1, O. Wieland13 and H. –J. Wollersheim1

Solar abundances reproduced by models Solar abundances reproduced by models which included shell quenching in the calculations.which included shell quenching in the calculations.

Possible causes: Monopole migration of the SPE levels in nuclei with extreme N/Z ratio

Not predicted by LSSM calculations

Diffuseness of the shape of the nuclear potential due to the neutron excess

Predicted in HFB calculations with Skyrme force in 122Zr Experimental evidences:Experimental evidences:

Flattening of the Cd 2+ systematics in 126Cd and 128Cd.

Possible onset of collectivity.Large Qβ value in 130Cd only reproduced by mass models which included

N = 82 shell quenching and indication of a low lying 2+ state at energy of 937 keV.

1 Gesellschaft für Schwerionenforschung (GSI), D-64291 Darmstadt, Germany2 Departamento de Física Teórica, Universidad Autonoma de Madrid, E-29049 Madrid, Spain3 Instituto de estructure de la Materia, CSIC, Serrano 113 bis, E-28006 Madrid, Spain4 IEP, Warsaw University, PL-00681 Warsaw, Poland5 IReS, IN2P3-CNRS / University Louis Pasteur, F-67037, Strasbourg, France6 Department of Physics, University of Surrey, Guildford, GU2 7XH, UK

7 Department of Physics, Lund University, S-22100 Lund, Sweden8 Faculty of Physics, University of Sofia, BG-1164 Sofia, Bulgaria9 School of Engineering, University of Brighton, Brighton, BN2 4GJ, UK10 KTH Stockholm, S-10691 Stockholm, Sweden11 The Henryk Niewodniczański Institute of Nuclear Physics, PL-31342 Kraków, Poland

12 Universidade de Santiago de Compostela, E-15782 Santiago de Compostela, Spain

13 INFN, Universitádegli Studi di Milano and INFN sezione di Milano, I-20133 Milano, Italy14 The Henryk Niewodniczański Institute of Nuclear Physics, PAN, 31-342 Kraków, Poland15 Institut für Kernphysik, Universität zu Köln, Germany16 Inter University Accelerator Centre, New Delhi, India17 LPSC, Université Joseph Fourier Grenoble 1, CNRS/IN2P3, Institut National Polytechnique de Grenoble, F-38026 Grenoble Cedex, France

112828CdCd

112626CdCd

LSSM126Cd

130Cd SM-2SM-1

T1/2= 1720(70) ns